Friction shock-absorbing mechanism



May 25 926.

S. B. HASELTINE FRICTION SHOCK ABSORBING MECHANISM File I -/7 74 2Sheets-Sheet 2 d August 4. 1924 y Mw E wv /H WV ,/MWMMWM//WM/ `PatentedMay 25, 1926?.

FRICTON SHQGKABSORBNG IMECHANISM.

Application filed August 4, 1924." Serial No1 729,8?42

This invention relates-to'y improvements in friction Ashockabsorbingmechanisms One object of the invention. istol providea frictionshock absorbing` mechanism',morev i particularly] adaptedforrailwaydraftjrig--I' gings, comprising a plurality of'fricti-on ele-l mentsand-wedge acting'means,wherein is obtained high capacity dueto irelatively large -frictional areas,together with preliml inary action ofthe wedge-friction means prior4 to -actu'alrelative' movement of thefriction elements.

increasing resistance during theremainder of the compressionl stroke.

Other objects and advantages of tliein l veiitionwill more fully andclearly appear-l fromtlie description and claims hereinafter following.

In thedrawings forming la part of this specification, Figurefl is alongitudinal,-horiy Zontal, sectional view `of a portion ofza railwaydraft rigging showing -my `improve- Y ments in connection therewith#Figure-2 is a front end, elevational view'of the shockv4 absorbingmechanism proper.- Figure 3 is a vertical, transverse,sectionalview-corre-- spoiidiiig substantially-to the line 3`3 `ofFigure l. Figure i is a detail, perspective view of a wedge frictionmember used Iin connection with my improved mechanism.

AndFigure 5 is a detail, perspective viewA of oneof the wedge frictionshoes -of said` mechanism.

Infsaid drawings, -10 indicate channelshaped center or draft sills of arailway carv underframe, to the inner faces ofwvliichy are secured frontstop lugs `ll--Fll andrearstop lugs iQlQ. A portion of -tlieidrawbar isindicated at 13, thesame being operatively: connected to a hooded yoke14, within -whichf the shock absorbing` mechanism properand a. frontfollower are contained'. Tl'ieyolze and the parts therewithin aresiippoi'tedin o p ate 16.'

The im i roved shoclr absorbin@ mechanismy proper.y as shown,com-prisesbroadly'a combined friction shell and spring cage castingyving ends of said element.

'tom sections 22.0f the elements E cooperate perative position by adetachable Saddle'.y

frictiony elementsl two wedgefriction elements v12-13; a pair ofwedge-'friction shoes ance J andy a retaint-irboltKi` 4 The casting IA,asy shown, is formedV with top and lbottom walls 17E-17, sidewalls.1S-"- 18, and-'anv integral rear walil"`l9, the latter functioning asthe rear Vfollower of the mech`` anism; The -sidev ;Walls18 are fleftcom'- parativelyshort,'so as'to leave the major a Awedgeibl'oclr' GH; 'a,second wedge block an auxiliary spring resist-Y .65, portion `of thesides of the casting open to`- permit thezinsertion andremovalof'certain parts of the'inechanisin; The side'wallslS areprovided on their inner faces with longi'" tndiiiallyl extendingfriction surfaces-20.

rlhet-wo movable friction elements vD are of like desi-gn, eachbeing :inthe form ofi? a relatively heavy plate= havingV a laterallyl extending,outwardlyprojecting fiangeQlfat "the rearY end thereof adapted to Vcoactwith the rear edge 'of the corresponding side wall 18 tolimit itsoutwardmovement. nThe parts are so proportionedthat when the plates D`are in their outermost position,as .most clearly shown iirFignre l, thefront endsthereo-f will rbe slightly spaced yfrom'the inner sur.

face Vofthe frontfollower v15. The outer" faces of the. elements DIcoa-et with the corresponding friction surfaces 20:0f t'heshell.'

The 'wedge' friction members E which are also of like' design,'arevdisposed on opposite' sidesl yof the mechanism; each cooperating withthe corresponding friction element D;

faces of saidelements converge inwardlyof the mechanism as most clearlyshown in Figurel. Each lnember E is provided with j' top andbottom,'horizontal`ly 'disposed plate; like sections 22projectingbeyond-the oppo1 lsite sides of the main body portion of theelement :E and having their front 'and rear edges spaced inwardly fromthe correspond- The topand botwithtransverse rib's23lprovided on the topthe inner and outer'ends of the friction shell portion thereof.' As mostclearly shown in Figures 2 and 3, the ribs 23 'at the'front end oftheshell extendentirely across the same, while the ribs at the rear end ofsaid shell are cut away centrally to provide openings 24 to permit theassembling of the mechanism. It lwill be evident that the ribscooperating with the plate sections 22 of the elements E serve toprevent longitudinal movement of the elements E with reference to thecasing A, but permit lateral displace ment of the same. 1

The friction wedge shoes F are also of like construction, each beingprovided at the front end thereof with a transverse flat face 124adapted to abut the inner surface of the front follower 15. Each shoe isalso provided with a longitudinally disposed outer friction surface 25correspondingly inclined to the inner surface of the correspond# ingelement E and adapted to cooperate therewith. On the side nearest theaxis of the shell, each shoe is cut away to provide a front wedge face2G anda rear wedge face 27, the front wedge faces 26 'of the two shoesdiverging inwardly of the mechanism and the rear wedge faces 27converging inwardly of the mechanism. Between the wedge faces 26 and 27,the inner surface of each shoe is concave, as shown, to accommodate theeor responding side of the auxiliary spring J and permit slightclearance to allow relative approach of the shoes F toward the centralaxis of the. mechanism.

The wedge block G is provided with a pair of wedge faces 126 at thefront end thereof, correspondingly inclined to the wedge faces 26 andadapted to cooperate therewith. T he wedge block H .is also providedwith a pair of wedge faces 127 correspondingly inclined to and adaptedto cooperate with the wedge faces 27 of the shoes F. Movement of thewedge members Gr and H relatively toward each other is yieldinglyresisted by the auxiliary spring J which is interposed therebetween.Said spring comprises a relatively light inner coil and a relativelyheavier outer coil having their opposite ends bearing on the wedgemembers Gr and H, respectively.

'lhe spring follower C is in the form of a relatively heavy rectangularplate having a central extension 28 at the front side thereof, saidextension having beveled edges 29-29 at the opposite sides thereofadapted to engage correspondingly beveled faces 128 at the inner ends ofthe shoes F. rlhe coop- @rating faces 29 and 12S offer resistance to thelateral approach of the shoes F, thus tending to give additionalresistance to collapse of wedge unit comprising the shoes F and wedgeblocks Gr and H. rlhe follower C is also provided with top and bottomribs engaging the inner ribs 23 of the casing A, limiting the outwardnovement of the spring follower and thereby maintaining the springresistance under initial compression. The main spring resistanceelements B comprise two sets of twin arranged springs, each twin springincluding an outer, relativelyy heavy coil and an inner relativelylighter coil bearing on the end wall 19 of the casing A and the innersurface of the spring follower C respectively.

The two wedge fric-tion shoes F, the wedge block G and the wedge blockH, together, form a collapsible wedge unit which is held in assembledrelation by the re tainer bolt l having its front and rear ends4anchored respectively to the wedge block (l and the spring follower C,the latter being provided with a recess 30, adapted to accommodate thehead of said bolt, the shank of the bolt extending through the innercoil of the spring resistance J and aligned openings in the wedgemembers Gr and H respectively. rfhe bolt K is so adjusted as to maintainthe parts of the collapsible wedge unit under initial compression and ofuniform overall length and the spring resistance J serves to yieldinglyresist collapse of said unit.

1n assembling the mechanism, the wedge friction members E are insertedinto the friction shell through the casing A, being inserted through theopenings in the sides of the latter, and then passed through theopenings 24 provided between the ribs 23 at the rear end of the frictionshell. This operation is preferably performed prior to the placing ofthe other parts within posi tion, however, the elements D may be placedin position either before or after the members E have been assembledwith the shell. The spring resistance elements 13 and the springfollower C are also inserted within the casing A through the openingsprovided in the opposite sides thereof.

The operation of my improved shock absorbing mechanism is as follows,assuming an inward or compression movement of the drawbar. During thetime that the pressure is transmitted through the shoes F to the springresistance elements B and the shoes are moved rearwardly therewith, awedging action will be set up between the shoes and the wedge members E,placing the friction elements D and the wedge elements` E under lateralpressure. At this time, the spring pressed wedge members G and H willyieldingly resist the collapse of the wedge unit comprising the shoes Fand said wedge blocks. As the wedge unit moves inwardly of the casing A,there will be an additional relative movement of the shoes F toward eachother, due to the converging relation of the inner surfaces of thefriction wedge members E, the coacting wedge faces 26 and 126 and 27 and127 slipping relatively, forcing the wedge blocks G and H toward eachother and compressing the auxiliary spring J. This action will continuethroughout the closing movement. After a limited movement as described,the main tlf) follower comes into engagement, with the front ends of thefriction elements D, whereupon the friction elements will be carriedrearwardly in unison with the follower', greatly augmenting the frictionresistance offered. InV this connection, it ijs pointed out that during'the initial action of the mechanism, the main spring follower will bemoved out of contact with the rear ends of the friction elements D andwill remain out of contact therewith during the remainder of thecompression stroke. The inward movement of the main follower and theparts actuated thereby will continue until the actuating force isremoved or the follower comes into abutment with the front end of thecasing A. W'hen the follower engages the casing A, the actuating forcewill be transmitted directly through the casing to the rear stop lugs,the casing acting as a stop column to prevent the springs from beingdriven solid.

When the actuating pressure is reduced, the main spring resistance Bwill return all of the parts to normal position and the auX- iliaryspring J will expand the collapsible wedge to its original size. In thisconnection, it is pointed out that the initial action during releasewill be an outward movement of `the wedge unit, due to the springfollower C being spaced from the inner ends of the friction elements Das hereinbefore pointed out. After the initial release action justdescribed, the spring follower C will pick up the friction elements Dand carry them outwardly to their normal position with the flanges 21thereof in engagement with the rear abutment faces of the side walls 18of the casing and their front ends spaced from the main 'follower 15.

I have herein shown and described what I now consider to be thepreferred manner of carrying out my invention, but the same is merelyillustrative and I contemplate all changes and modifications that comewithin the scope of the claims appended hereto.

I claim:

1. In a friction shock absorbing mechanism, the combination with afriction shell having interior, longitudinally disposed frictionsurfaces; of cooperating relatively movable friction elements withinsaid shell, certain of said elements engaging the shell frictionsurfaces and the remaining elements being tapered and having innerfriction surfaces inclined with reference to the axis of the mechanism;an expandible and contractible wedge pressure transmitting unit; a mainspring resistance opposing inward movement of said wedge unit; andyielding means acting independently of said main spring resistancetending to maintain the unit expanded.

2. In a friction shock absorbing mechanism, the combination with a mainfollower;

of a friction, shell having meansy thereon presenting longitudinallydisposed, interior, inwardly converging friction surfaces; a frictionunit cooperating with said friction surfaces., said unit including apair of friction wedge shoes engaged by said follower, and a pair ofwedge blocks, said wedge blocks and slices having cooperating sets ofwedge faces; a, main Spring resistance; and a spring resistanceinterposed between said wedge blocks.

3. I n a friction shock absorbing mechanism, the combination with afriction shell having mea-ns thereon presenting interior, longitudinallydisposed, inwardly converging friction surfaces; a friction unitincluding friction sho-es, a pair of wedge blocks and a springresistance, Asaid shoes cooperating with said friction surfaces and eachhaving wedge faces at the front and rear ends thereof cooperatingrespectively with said wedge blocks, said spring resistance beinginterposed between said wedge blocks; and a main spring resistance forsaid friction unit.

t. In a friction shock absorbing mecha.- nism, the combination with afriction shell having interior, friction surfaces; of a main springresistance; relatively movable, longitudinally disposed frictionelements cooperating with said .shell friction surfaces; longitudinallydisposed friction members cooperating with said friction elements;friction shoes cooperating with said friction members, .said shoeshaving wedge faces at the front and rear ends thereof; wedge blockscooperating with said front and rear wedge faces; and a springresistance interposed between said wedge blocks.

5. In a friction shock absorbing mechanism, the combination with afriction shell having interior friction surfaces; of a main springresistance; relatively movable, longitudinally disposed frictionelements cooperating with said shell friction surfaces; longitudinallydisposed, wedge friction members cooperatingV with said frictionelements; friction shoes cooperating with said friction members, saidshoes having wedge faces at the front and rear ends thereof wedge blockscooperating with said front and rear wedge faces; and a springresistance interposed between said wedge blocks.

6. In a friction shock absorbing mechanism, the combination with afriction shell having opposed interior friction surfaces; of a mainspring resistance; an elongated friction element cooperating with eachshell friction surface; a pair of friction wedge shoes, said shoes eachhavingfront and rear interior wedge faces; a tapered friction blockinterposed between each shoe and element; wedge blocks cooperating withthe wedge faces at the opposite ends of said shoes; an auxiliary springresistance interposed between said blocls; and a spring fol-@blockinterposed between each shoe and elelower interposed between said mainspring resistance and the inner ends of said shoes.

7. In a friction shock absorbing mechanism, the combination with a mainfollower; of a friction shell having opposed interior friction surfaces;a main spring resistance; an elongated friction element cooperating`with each shell friction surface; stop means limiting the outwardmovement o-f said elements and maintaining the same normally spaced fromsaid follower; a pair of friction wedge shoes bearing on said follower,the said shoes each having front and rear interior wedge faces; atapered friction ment; wedge blocks cooperating with the wedge faces atthe opposite ends of said shoes; a .second spring resistance interposedbetween said blocks; and a spring follower interposed between said mainspring resistance and the inner ends of said shoes, said followernormally engaging said friction elements to hold the latter in abutmentwith said .stop means.

In witness that I claim the foregoing I have hereunto subscribed my namethis 31st day of July 1924.

STACY B. HASELTINE.

